Systems and methods for transmitting and receiving discovery and paging messages

ABSTRACT

Methods, devices, and computer program products for transmitting and receiving discovery and paging messages are described herein. In one aspect, an apparatus operable in a wireless communication system includes a transmitter and receiver. The transmitter transmits a discovery packet during a first discovery interval of a plurality of discovery intervals. The discovery packet advertises a service provided in a wireless communications network, and the plurality of discovery intervals include recurring time intervals when a plurality of devices are configured to transmit and receive discovery packets. The receiver receives a paging packet from a first device during a first paging interval of a plurality of paging intervals. The paging packet indicates interest in the service, and the plurality of paging intervals include recurring time intervals when the plurality of devices are configured to transmit and receive paging packets. The plurality of paging intervals do not overlap the plurality of discovery intervals.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. §119(e) to U.S.Provisional Patent Application No. 61/570,704 entitled “SYSTEMS ANDMETHODS FOR TRANSMITTING AND RECEIVING DISCOVERY AND PAGING MESSAGES”filed on Dec. 14, 2011; the disclosure of which is hereby incorporatedby reference in its entirety.

FIELD

The present application relates generally to wireless communications,and more specifically to systems, methods, and devices for transmittingand receiving discovery and paging messages.

BACKGROUND

In many telecommunication systems, communications networks are used toexchange messages among several interacting spatially-separated devices.Networks may be classified according to geographic scope, which couldbe, for example, a metropolitan area, a local area, or a personal area.Such networks would be designated respectively as a wide area network(WAN), metropolitan area network (MAN), local area network (LAN),wireless local area network (WLAN), or personal area network (PAN).Networks also differ according to the switching/routing technique usedto interconnect the various network nodes and devices (e.g. circuitswitching vs. packet switching), the type of physical media employed fortransmission (e.g. wired vs. wireless), and the set of communicationprotocols used (e.g. Internet protocol suite, SONET (Synchronous OpticalNetworking), Ethernet, etc.).

Wireless networks are often preferred when the network elements aremobile and thus have dynamic connectivity needs, or if the networkarchitecture is formed in an ad hoc, rather than fixed, topology.Wireless networks employ intangible physical media in an unguidedpropagation mode using electromagnetic waves in the radio, microwave,infra-red, optical, etc. frequency bands. Wireless networksadvantageously facilitate user mobility and rapid field deployment whencompared to fixed wired networks.

The devices in a wireless network may transmit or receive informationbetween one other. The information may comprise packets, which may bereferred to as data units. The packets may include overhead information(e.g., header information, packet properties, etc.) that helps inrouting the packet through the network, identifying the data in thepacket, processing the packet, etc., as well as data, for example userdata, multimedia content, etc. as might be carried in a payload of thepacket. Additionally, packets may be used to introduce two differentdevices communicating on a communication medium. The communicationmedium may be shared by multiple devices seeking to access thecommunication medium.

SUMMARY

The systems, methods, devices, and computer program products discussedherein each have several aspects, no single one of which is solelyresponsible for its desirable attributes. Without limiting the scope ofthis invention as expressed by the claims which follow, some featuresare discussed briefly below. After considering this discussion, andparticularly after reading the section entitled “Detailed Description,”it will be understood how advantageous features of this inventioninclude reduced power consumption when introducing devices on a medium.

One aspect of this disclosure provides a method of wirelesscommunication performed by an apparatus. The method includes:transmitting a discovery packet during a first discovery interval of aplurality of discovery intervals, the discovery packet advertising aservice provided in a wireless communications network, the plurality ofdiscovery intervals comprising recurring time intervals when a pluralityof devices are configured to transmit and receive discovery packets; andreceiving a paging packet from a first device during a first paginginterval of a plurality of paging intervals, the paging packetindicating interest in the service, the plurality of paging intervalscomprising recurring time intervals when the plurality of devices areconfigured to transmit and receive paging packets, the plurality ofpaging intervals not overlapping the plurality of discovery intervals.

Another aspect of this disclosure provides a method of discoveringdevices in a wireless communication system performed by an apparatus.The method includes: receiving a discovery packet from a first deviceduring a first discovery interval of a plurality of discovery intervals,the discovery packet advertising a service provided by the first devicein a wireless communications network, the plurality of discoveryintervals comprising recurring time intervals when a plurality ofdevices are configured to transmit and receive discovery packets; andtransmitting a paging packet to the first device during a first paginginterval of a plurality of paging intervals, the paging packetindicating interest in the service provided by the first device, theplurality of paging intervals comprising recurring time intervals whenthe plurality of devices are configured to transmit and receive pagingpackets, the plurality of paging intervals not overlapping the pluralityof discovery intervals.

One aspect of this disclosure provides an apparatus operable in awireless communication system. The apparatus includes a transmitter andreceiver. The transmitter is configured to transmit a discovery packetduring a first discovery interval of a plurality of discovery intervals.The discovery packet advertises a service provided in a wirelesscommunications network, and the plurality of discovery intervals includerecurring time intervals when a plurality of devices are configured totransmit and receive discovery packets. The receiver is configured toreceive a paging packet from a first device during a first paginginterval of a plurality of paging intervals. The paging packet indicatesinterest in the service, and the plurality of paging intervalscomprising recurring time intervals when the plurality of devices areconfigured to transmit and receive paging packets. The plurality ofpaging intervals do not overlap the plurality of discovery intervals.

Another aspect of this disclosure provides an apparatus operable in awireless communication system. The apparatus includes a receiver andtransmitter. The receiver is configured to receive a discovery packetfrom a first device during a first discovery interval of a plurality ofdiscovery intervals. The discovery packet advertises a service providedby the first device in a wireless communications network, and theplurality of discovery intervals include recurring time intervals when aplurality of devices are configured to transmit and receive discoverypackets. The transmitter is configured to transmit a paging packet tothe first device during a first paging interval of a plurality of pagingintervals. The paging packet indicates interest in the service providedby the first device, and the plurality of paging intervals includerecurring time intervals when the plurality of devices are configured totransmit and receive paging packets. The plurality of paging intervalsdo not overlap the plurality of discovery intervals.

One aspect of this disclosure provides an apparatus operable in awireless communication system. The apparatus includes: means fortransmitting a discovery packet during a first discovery interval of aplurality of discovery intervals, the discovery packet advertising aservice provided in a wireless communications network, the plurality ofdiscovery intervals comprising recurring time intervals when a pluralityof devices are configured to transmit and receive discovery packets; andmeans for receiving a paging packet from a first device during a firstpaging interval of a plurality of paging intervals, the paging packetindicating interest in the service, the plurality of paging intervalscomprising recurring time intervals when the plurality of devices areconfigured to transmit and receive paging packets, the plurality ofpaging intervals not overlapping the plurality of discovery intervals.

Another aspect of this disclosure provides an apparatus operable in awireless communication system. The apparatus includes: means forreceiving a discovery packet from a first device during a firstdiscovery interval of a plurality of discovery intervals, the discoverypacket advertising a service provided by the first device in a wirelesscommunications network, the plurality of discovery intervals comprisingrecurring time intervals when a plurality of devices are configured totransmit and receive discovery packets; and means for transmitting apaging packet to the first device during a first paging interval of aplurality of paging intervals, the paging packet indicating interest inthe service provided by the first device, the plurality of pagingintervals comprising recurring time intervals when the plurality ofdevices are configured to transmit and receive paging packets, theplurality of paging intervals not overlapping the plurality of discoveryintervals.

One aspect of this disclosure provides a non-transitorycomputer-readable medium comprising instructions that when executedcause an apparatus to: transmit a discovery packet during a firstdiscovery interval of a plurality of discovery intervals, the discoverypacket advertising a service provided in a wireless communicationsnetwork, the plurality of discovery intervals comprising recurring timeintervals when a plurality of devices are configured to transmit andreceive discovery packets; and receive a paging packet from a firstdevice during a first paging interval of a plurality of pagingintervals, the paging packet indicating interest in the service, theplurality of paging intervals comprising recurring time intervals whenthe plurality of devices are configured to transmit and receive pagingpackets, the plurality of paging intervals not overlapping the pluralityof discovery intervals.

Another aspect of this disclosure provides a non-transitorycomputer-readable medium comprising instructions that when executedcause an apparatus to: receive a discovery packet from a first deviceduring a first discovery interval of a plurality of discovery intervals,the discovery packet advertising a service provided by the first devicein a wireless communications network, the plurality of discoveryintervals comprising recurring time intervals when a plurality ofdevices are configured to transmit and receive discovery packets; andtransmit a paging packet to the first device during a first paginginterval of a plurality of paging intervals, the paging packetindicating interest in the service provided by the first device, theplurality of paging intervals comprising recurring time intervals whenthe plurality of devices are configured to transmit and receive pagingpackets, the plurality of paging intervals not overlapping the pluralityof discovery intervals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communication system inwhich aspects of the present disclosure may be employed.

FIG. 2 shows a functional block diagram of a wireless device that may beemployed within the wireless communication system of FIG. 1.

FIG. 3 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 4 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 5 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 6 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 7 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 8 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 9 illustrates an exemplary communication timeline in a wirelesscommunication system in accordance with aspects of the presentdisclosure.

FIG. 10 illustrates an exemplary discovery packet in accordance withaspects of the present disclosure.

FIG. 11 illustrates another exemplary discovery packet in accordancewith aspects of the present disclosure.

FIG. 12 illustrates an exemplary paging request packet in accordancewith aspects of the present disclosure.

FIG. 13 illustrates an exemplary registration action frame in accordancewith aspects of the present disclosure.

FIG. 14 illustrates an exemplary paging forwarding action frame inaccordance with aspects of the present disclosure.

FIG. 15 illustrates an exemplary paging response forwarding action framein accordance with aspects of the present disclosure.

FIG. 16 is a graph illustrating an example cumulative distributionfunction for successfully transmitting a discovery packet by contentionin accordance with aspects of the present disclosure.

FIG. 17 is another graph illustrating an example cumulative distributionfunction for successfully transmitting a discovery packet by contentionin accordance with aspects of the present disclosure.

FIG. 18 is a yet another graph illustrating an example cumulativedistribution function for successfully transmitting a discovery packetby contention in accordance with aspects of the present disclosure.

FIG. 19 is an additional graph illustrating an example cumulativedistribution function for successfully transmitting a discovery packetby contention in accordance with aspects of the present disclosure.

FIG. 20 is a graph illustrating an example probability of successfunction for successfully transmitting a discovery packet by random slotselection in accordance with aspects of the present disclosure.

FIG. 21 is a flowchart of an exemplary process of discovering devices ina wireless communication system in accordance with aspects of thepresent disclosure.

FIG. 22 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.

FIG. 23 is a flowchart of an exemplary process of discovering devices ina wireless communication system in accordance with aspects of thepresent disclosure.

FIG. 24 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.

FIG. 25 is a flowchart of an exemplary process of discovering devices ina wireless communication system using an access point in accordance withaspects of the present disclosure.

FIG. 26 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.

FIG. 27 is a flowchart of an exemplary process of discovering devices ina wireless communication system using an access point in accordance withaspects of the present disclosure.

FIG. 28 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.

FIG. 29 is a flowchart of an exemplary process of discovering devices ina wireless communication system using an access point in accordance withaspects of the present disclosure.

FIG. 30 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.

DETAILED DESCRIPTION

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. Various aspects of the novelsystems, apparatuses, and methods are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the novel systems,apparatuses, and methods disclosed herein, whether implementedindependently of, or combined with, any other aspect of the invention.For example, an apparatus may be implemented or a method may bepracticed using any number of the aspects set forth herein. In addition,the scope of the invention is intended to cover such an apparatus ormethod which is practiced using other structure, functionality, orstructure and functionality in addition to or other than the variousaspects of the invention set forth herein. It should be understood thatany aspect disclosed herein may be embodied by one or more elements of aclaim.

Although particular aspects are described herein, many variations andpermutations of these aspects fall within the scope of the disclosure.Although some benefits and advantages of the preferred aspects arementioned, the scope of the disclosure is not intended to be limited toparticular benefits, uses, or objectives. Rather, aspects of thedisclosure are intended to be broadly applicable to different wirelesstechnologies, system configurations, networks, and transmissionprotocols, some of which are illustrated by way of example in thefigures and in the following description of the preferred aspects. Thedetailed description and drawings are merely illustrative of thedisclosure rather than limiting, the scope of the disclosure beingdefined by the appended claims and equivalents thereof.

Popular wireless network technologies may include various types ofwireless local area networks (WLANs). A WLAN may be used to interconnectnearby devices together, employing widely used networking protocols. Thevarious aspects described herein may apply to any communicationstandard, such as a wireless protocol.

In some aspects, wireless signals in a sub-gigahertz band may betransmitted according to the 802.11ah protocol using orthogonalfrequency-division multiplexing (OFDM), direct-sequence spread spectrum(DSSS) communications, a combination of OFDM and DSSS communications, orother schemes. Implementations of the 802.11ah protocol may be used forsensors, metering, and smart grid networks. Advantageously, aspects ofcertain devices implementing the 802.11ah protocol may consume lesspower than devices implementing other wireless protocols, and/or may beused to transmit wireless signals across a relatively long range, forexample about one kilometer or longer.

In some implementations, a WLAN includes various devices which are thecomponents that access the wireless network. For example, there may betwo types of devices: access points (“APs”) and clients (also referredto as stations, or “STAs”). In general, an AP may serve as a hub or basestation for the WLAN and a STA serves as a user of the WLAN. Forexample, a STA may be a laptop computer, a personal digital assistant(PDA), a mobile phone, etc. In an example, a STA connects to an AP via aWiFi (e.g., IEEE 802.11 protocol such as 802.11ah) compliant wirelesslink to obtain general connectivity to the Internet or to other widearea networks. In some implementations a STA may also be used as an AP.

An access point (“AP”) may also comprise, be implemented as, or known asa NodeB, Radio Network Controller (“RNC”), eNodeB, Base StationController (“BSC”), Base Transceiver Station (“BTS”), Base Station(“BS”), Transceiver Function (“TF”), Radio Router, Radio Transceiver, orsome other terminology.

A station “STA” may also comprise, be implemented as, or known as anaccess terminal (“AT”), a subscriber station, a subscriber unit, amobile station, a remote station, a remote terminal, a user terminal, auser agent, a user device, user equipment, or some other terminology. Insome implementations an access terminal may comprise a cellulartelephone, a cordless telephone, a Session Initiation Protocol (“SIP”)phone, a wireless local loop (“WLL”) station, a personal digitalassistant (“PDA”), a handheld device having wireless connectioncapability, or some other suitable processing device connected to awireless modem. Accordingly, one or more aspects taught herein may beincorporated into a phone (e.g., a cellular phone or smartphone), acomputer (e.g., a laptop), a portable communication device, a headset, aportable computing device (e.g., a personal data assistant), anentertainment device (e.g., a music or video device, or a satelliteradio), a gaming device or system, a global positioning system device,or any other suitable device that is configured to communicate via awireless medium.

As discussed above, certain of the devices described herein mayimplement the 802.11ah standard, for example. Such devices, whether usedas a STA or AP or other device, may be used for smart metering or in asmart grid network. Such devices may provide sensor applications or beused in home automation. The devices may instead or in addition be usedin a healthcare context, for example for personal healthcare. They mayalso be used for surveillance, to enable extended-range Internetconnectivity (e.g. for use with hotspots), or to implementmachine-to-machine communications.

FIG. 1 illustrates an example of a wireless communication system 100 inwhich aspects of the present disclosure may be employed. The wirelesscommunication system 100 may operate pursuant to a wireless standard,for example the 802.11ah standard. The wireless communication system 100may include an AP 104, which communicates with STAs 106. In someaspects, the wireless communication system 100 may include more than oneAP. Additionally, the STAs 106 may communicate with other STAs 106. Asan example, a first STA 106 a may communicate with a second STA 106 b.As another example, a first STA 106 a may communicate with a third STA106 c although this communication link is not illustrated in FIG. 1.

A variety of processes and methods may be used for transmissions in thewireless communication system 100 between the AP 104 and the STAs 106and between an individual STA, such as the first STA 106 a, and anotherindividual STA, such as the second STA 106 b. For example, signals maybe sent and received in accordance with OFDM/OFDMA techniques. If thisis the case, the wireless communication system 100 may be referred to asan OFDM/OFDMA system. Alternatively, signals may be sent and receivedbetween the AP 104 and the STAs 106 and between an individual STA, suchas the first STA 106 a, and another individual STA, such as the secondSTA 106 b, in accordance with CDMA techniques. If this is the case, thewireless communication system 100 may be referred to as a CDMA system.

A communication link that facilitates transmission from the AP 104 toone or more of the STAs 106 may be referred to as a downlink (DL) 108,and a communication link that facilitates transmission from one or moreof the STAs 106 to the AP 104 may be referred to as an uplink (UL) 110.Alternatively, a downlink 108 may be referred to as a forward link or aforward channel, and an uplink 110 may be referred to as a reverse linkor a reverse channel.

A communication link may be established between STAs. Some communicationlinks between STAs are illustrated in FIG. 1. As an example, acommunication link 112 may facilitate transmission from the first STA106 a to the second STA 106 b. Another communication link 114 mayfacilitate transmission from the second STA 106 b to the first STA 106a.

The AP 104 may act as a base station and provide wireless communicationcoverage in a basic service area (BSA) 102. The AP 104 along with theSTAs 106 associated with the AP 104 and that use the AP 104 forcommunication may be referred to as a basic service set (BSS). It shouldbe noted that the wireless communication system 100 may not have acentral AP 104, but rather may function as a peer-to-peer networkbetween the STAs 106. Accordingly, the functions of the AP 104 describedherein may alternatively be performed by one or more of the STAs 106.

FIG. 2 illustrates various components that may be utilized in a wirelessdevice 202 that may be employed within the wireless communication system100. The wireless device 202 is an example of a device that may beconfigured to implement the various methods described herein. Forexample, the wireless device 202 may comprise the AP 104 or one of theSTAs 106.

The wireless device 202 may include a processor 204 which controlsoperation of the wireless device 202. The processor 204 may also bereferred to as a central processing unit (CPU). Memory 206, which mayinclude both read-only memory (ROM) and random access memory (RAM), mayprovide instructions and data to the processor 204. A portion of thememory 206 may also include non-volatile random access memory (NVRAM).The processor 204 typically performs logical and arithmetic operationsbased on program instructions stored within the memory 206. Theinstructions in the memory 206 may be executable to implement themethods described herein.

The processor 204 may comprise or be a component of a processing systemimplemented with one or more processors. The one or more processors maybe implemented with any combination of general-purpose microprocessors,microcontrollers, digital signal processors (DSPs), field programmablegate array (FPGAs), programmable logic devices (PLDs), controllers,state machines, gated logic, discrete hardware components, dedicatedhardware finite state machines, or any other suitable entities that canperform calculations or other manipulations of information.

The processing system may also include machine-readable media forstoring software. Software shall be construed broadly to mean any typeof instructions, whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise. Instructions mayinclude code (e.g., in source code format, binary code format,executable code format, or any other suitable format of code). Theinstructions, when executed by the one or more processors, cause theprocessing system to perform the various functions described herein.

The wireless device 202 may also include a housing 208 that may includea transmitter 210 and/or a receiver 212 to allow transmission andreception of data between the wireless device 202 and a remote location.The transmitter 210 and receiver 212 may be combined into a transceiver214. An antenna 216 may be attached to the housing 208 and electricallycoupled to the transceiver 214. The wireless device 202 may also include(not shown) multiple transmitters, multiple receivers, multipletransceivers, and/or multiple antennas.

The transmitter 210 may be configured to wirelessly transmit packetshaving different packet types or functions. For example, the transmitter210 may be configured to transmit packets of different types generatedby the processor 204. When the wireless device 202 is implemented orused as an AP 104 or STA 106, the processor 204 may be configured toprocess packets of a plurality of different packet types. For example,the processor 204 may be configured to determine the type of packet andto process the packet and/or fields of the packet accordingly. When thewireless device 202 is implemented or used as an AP 104, the processor204 may also be configured to select and generate one of a plurality ofpacket types. For example, the processor 204 may be configured togenerate a discovery packet comprising a discovery message and todetermine what type of packet information to use in a particularinstance.

The receiver 212 may be configured to wirelessly receive packets havingdifferent packet types. In some aspects, the receiver 212 may beconfigured to detect a type of a packet received and to process thepacket accordingly.

The wireless device 202 may also include a signal detector 218 that maybe used to detect and quantify the level of signals received by thetransceiver 214. The signal detector 218 may detect such signals astotal energy, energy per subcarrier per symbol, power spectral densityand other signals. The wireless device 202 may also include a digitalsignal processor (DSP) 220 for use in processing signals. The DSP 220may be configured to generate a packet for transmission. In someaspects, the packet may comprise a physical layer data unit (PPDU).

The wireless device 202 may further comprise a user interface 222 insome aspects. The user interface 222 may comprise a keypad, amicrophone, a speaker, and/or a display. The user interface 222 mayinclude any element or component that conveys information to a user ofthe wireless device 202 and/or receives input from the user.

The various components of the wireless device 202 may be coupledtogether by a bus system 226. The bus system 226 may include a data bus,for example, as well as a power bus, a control signal bus, and a statussignal bus in addition to the data bus. The components of the wirelessdevice 202 may be coupled together or accept or provide inputs to eachother using some other mechanism.

Although a number of separate components are illustrated in FIG. 2, oneor more of the components may be combined or commonly implemented. Forexample, the processor 204 may be used to implement not only thefunctionality described above with respect to the processor 204, butalso to implement the functionality described above with respect to thesignal detector 218 and/or the DSP 220. Further, each of the componentsillustrated in FIG. 2 may be implemented using a plurality of separateelements.

To ensure proper communication between devices such as AP 104 and theSTAs 106, the AP 104 or STAs 106 may require information regardingcharacteristics of the AP 104 or STAs 106. For example, the STA 106 mayrequire timing information about the AP 104 in order to synchronizetiming of communication between the STA 106 and the AP 104. Additionallyor alternatively, the STA 106 may require other information such as amedia access control (MAC) address of the AP 104, an identifier of thebasic service set (BSS) served by the AP 104, etc. The STA 106 maydetermine whether it needs such information independently, such asthrough software running using memory 206 and processor 204.

The AP 104 or STA 106 may have a plurality of operational modes. Forexample, the STA 106 may have a first operational mode referred to as anactive mode, normal operation mode, or full power mode. In the activemode, the AP 104 or STA 106 may always be in an “awake” state andactively transmit/receive data with another STA 106. Further, the STA106 may have a second operational mode referred to as a power-save modeor sleep mode. In the power-save mode, the AP104 or STA 106 may be inthe “awake” state or a “doze” or “sleep” state where the AP 104 or STA106 does not actively transmit/receive data with another STA 106. Forexample, the receiver 212 and possibly DSP 220 and signal detector 218of the STA 106 may operate using reduced power consumption in the dozestate. Further, in the power-save mode, a STA 106 may occasionally enterthe awake state to listen to messages from an AP 104 (e.g., pagingmessages) that indicate to the STA 106 whether or not the STA 106 needsto “wake up” (e.g., enter the awake state) at a certain time so as to beable to transmit/receive data with the AP 104 or another STA.

FIG. 3 illustrates an exemplary communication timeline 300 in a wirelesscommunication system where devices may communicate via a channel. Theexemplary communication timeline 300 may include a discovery interval(DI) 302 of a time duration ΔA, a paging interval (PI) 304 of a timeduration ΔB, and an overall interval of a time duration ΔC. In someaspects, communications may occur via other channels as well. Timeincreases horizontally across the page over the time axis.

During the DI 302, APs or STAs may advertise through messages, such asdiscovery packets, services (e.g., features of applications shared byAPs or STAs) that are provided in the wireless communication system. APsor STAs may further listen to broadcast messages transmitted by otherAPs or STAs. In some aspects, a STA may register with an AP or STAduring or outside of the DI 302. After registering, the AP or STA maytransmit or receive messages on behalf of the registered STA. In someaspects, the duration of DIs may vary over time. In other aspects, theduration of the DI 302 may remain fixed over a period of time.

The end of the DI 302 may be separated from the beginning of thesubsequent PI 304 by a first remainder period of time as illustrated inFIG. 3. The end of the PI 304 may be separated from the beginning of asubsequent DI 302 by a remainder period of time having the same ordifferent length as the first remainder period of time.

During the PI 304, APs or STAs may indicate interest in one or more of aplurality of services advertised in a broadcast message by transmittingpaging request messages, such as paging request packets or pagingpackets. APs or STAs may listen to paging request messages transmittedby other APs or STAs. In some aspects, the duration of the PI 304 mayvary over time. In other aspects, the duration of the PI 304 may remainconstant over a period of time. In some aspects, the duration of the PI304 may be shorter than the duration of the DI 302.

The overall interval of duration ΔC may measure the period of time fromthe beginning of one DI 302 to the beginning of a subsequent DI 302 asillustrated in FIG. 3. In some aspects, the duration of the overallinterval may vary over time. In other aspects, the duration of theoverall interval may remain constant over a period of time. At theconclusion of the overall interval of duration ΔC, another overallinterval may begin, including a DI 302, a PI 304, and the remainderintervals. Consecutive overall intervals may follow indefinitely orcontinue for a fixed period of time.

A STA may enter a sleep or power-save mode when the STA is nottransmitting or listening or expecting to soon transmit or listen. As anexample, the STA may sleep during periods other than the DI 302 or PI304. The STA in the sleep mode or power-save mode may awake or return tonormal operation or full power mode at the beginning of the DI 302 or PI304 to enable transmission or listening by the STA. In some aspects, theSTA may awake or return to normal operation or full power mode at othertimes when the STA expects to communicate with another device, or as aresult of receiving a notification packet instructing the STA to awake.The STA may awake early to ensure that the STA receives a transmission.

FIG. 4 illustrates an exemplary communication timeline in a wirelesscommunication system where devices may communicate via a channel. Theexemplary communication timeline 400 may include a DI 402 of a timeduration ΔA, a PI 404 of a time duration ΔB, and an overall interval ofa time duration ΔC. Time increases horizontally across the page over thetime axis. As illustrated in FIG. 4, the beginning of a PI 404 mayimmediately follow the end of a DI 402. The end of the PI 404 may beseparated from the beginning of a subsequent DI by a remainder period oftime equal to ΔC less the sum of ΔB and ΔA.

FIG. 5 illustrates an exemplary communication timeline 500 in a wirelesscommunication system where devices may communicate via a channel. Theexemplary communication timeline 500 may include a DI 502 of a timeduration ΔA, a PI 504 of a time duration ΔB, and an overall interval ofa time duration ΔC. Time increases horizontally across the page over thetime axis. During the DI 502, APs or STAs may transmit discovery packets(DPs). During the PI 504, APs or STAs may transmit paging requestpackets (PRs). A DP may be a packet configured to advertise a pluralityof services provided by a STA or AP and to indicate when the paginginterval is for the device that transmits the DP. The DP may have afixed or variable size and include a data frame, management frame, ormanagement action frame. The DP may carry information generated by ahigher layer discovery protocol or an application-based discoveryprotocol. The PR may have a fixed or variable size and be a packetconfigured to indicate interest in at least one of the plurality ofservices provided by an AP or STA.

The communication channel may be cleared of devices communicating usinglegacy protocols during the DI 502 and PI 504 of packets, in someaspects, by transmitting special clear to send (S-CTS) frames. A S-CTSframe may instruct devices using legacy protocols to refrain fromsending data for a given time. However, the S-CTS may still allowdevices to send discovery packets and paging request packets.

The APs and STAs may contend for use of the channel during the DI 502and PI 504 to determine which APs and/or STAs may transmit DPs or PRs ata particular time. In some aspects, the contention method utilized mayinclude carrier sense multiple access (CSMA). CSMA may be aprobabilistic Media Access Control (MAC) protocol in which an AP or STAverifies the absence of other traffic before transmitting a packet onthe shared transmission channel. In other aspects, the contention methodutilized may include CSMA with collision avoidance (CSMA/CA). Under theCSMA/CA approach, if the channel may be sensed as busy, transmission maybe deferred for an interval. The deferred interval may be random ordetermined using another scheme such as an interval lookup table.CSMA/CA may be the default 802.11 MAC approach. Utilizing a contentionapproach may provide the benefit of enabling fixed overhead to scalelinearly with the number of devices in the wireless communication systemas opposed to scaling based on the number of devices squared.Additionally, a contention approach may be used to determine whendevices may transmit packets outside of the DI 502 or PI 504. In somecases, a contention approach may further provide beneficial flexibilityparticularly when the clocks of communicating devices may not be tightlysynchronized.

The start and end of the DI 502 and PI 504 may be known via variousmethods to each STA desiring to transmit a discovery packet or a pagingrequest packet. In some aspects, each STA may synchronize its clock withthe other APs or STAs and thereby also receive an indication of the DI502 and PI 504 start time and DI 502 duration and PI 504 duration. Inother aspects, a device may send a signal such as a S-CTS signal toclear the channel or medium of legacy communications, such ascommunications that may conflict or not be compliant with aspects of thepresent disclosure, and indicate the beginning and duration of the DI502 or PI 504 period, as well as additional information about the DI 502and PI 504 durations.

As an example, FIG. 5 depicts that devices may contend to transmit threediscovery packets on the channel during the DI 502. The three discoverypackets may be transmitted by up to three different STAs. If the threediscovery packets are transmitted by more than one STA, the STAs may usea CSMA/CA approach to determine which packet may be transmitted at aparticular time. The STAs may have synchronized clocks and may havepreviously communicated a shared DI 502 duration such that each STA maybe aware of the approximate DI 502 start and end time. In some aspects,each STA desiring to transmit a discovery packet may select a randominitial transmission time within the DI 502 to attempt to transmit adiscovery packet or packets. In other aspects, the STA may select apredetermined or scheduled initial transmission time. Beforetransmitting, each STA may sense the medium for a period of time todetermine whether a communication may be currently in progress on thechannel. In some aspects, the STA may sense the medium for approximately25 μs. If the medium may be clear, the STA may transmit a discoverypacket such as discovery packet (DP) 512. If the medium may not beclear, the STA may delay transmitting the discovery packet for a delayperiod. The delay period may be random in some aspects while calculatedor predetermined in other aspects. After the delay period, the STA mayagain sense the medium, and if the medium may be clear, the STA maytransmit the discovery packet. If the medium may not be clear, the STAmay repeat the delay and sense process until the discovery packet may besuccessfully sent.

The process of sending a paging request packet during the PI 504 maysimilar to the process described above with respect to transmitting adiscovery packet during the DI 502. As an example, FIG. 5 depicts thatdevices may contend to transmit three paging request packets on thechannel during the PI 504. The three paging request packets may betransmitted by up to three different STAs. If the three discoverypackets are transmitted by more than one STA, the STAs may use a CSMA/CAapproach to determine which packets may be transmitted at a particulartime. The STAs may have synchronized clocks and may have previouslycommunicated a shared PI 504 duration such that each STA may be aware ofthe approximate PI 504 start and end time. In some aspects, each STAdesiring to transmit a paging request packet may select a random initialtransmission time within the PI 504 to attempt to transmit its pagingrequest packet or packets. Before transmitting, each STA may sense themedium to determine whether a communication may be currently in progresson the channel. In some aspects, the STA may sense the medium forapproximately 25 μs. If the medium may be clear, the STA may transmit apaging request packet such as paging request packet (PR) 514. If themedium may not be clear, the STA may delay transmitting the pagingrequest packet for a delay period. The delay period may be random insome aspects while calculated or predetermined in other aspects. Afterthe delay period, the STA may again sense the medium, and if the mediummay be clear, the STA may transmit the paging request packet. If themedium may not be clear, the STA may repeat the delay and sense processuntil the paging request packet may be successfully sent.

STAs interested in services advertised via discovery packets, such as atleast one of the plurality of services advertised in DP 512, may awakeor remain awake during the DI 502 and process discovery packets todetermine if a particular discovery packet may contain information aboutone or more of a plurality of services of interest provided by a device.After the DI 502 period, STAs not planning to communicate informationmay enter a sleep or power-save mode until the next time the STAs planto communicate. In some aspects, a STA may enter the sleep or power-savemode until the STA communicates information with another device outsideof the DI 502 or PI 504. In some aspects, the STA may enter the sleep orpower-save mode until the beginning of the next PI 504. At the beginningof the PI 504, the interested STA may awake to transmit a paging requestpacket to the provider of the service.

STAs waiting for responses to a transmitted discovery packet, such asthe plurality of services advertised in DP 512, may awake or remainawake during the PI 504 and process paging request packets, such as PR514, to determine if a particular paging request packet indicatesinterest by another device in at least one of plurality of servicesprovided by the STA. After the PI 504 period, STAs not planning tocommunicate information may enter a sleep or power-save mode until thenext time the STAs plan to communicate. In some aspects, a STA may enterthe sleep or power-save mode until the STA may communicate additionalinformation with another device outside of the DI 502 or PI 504. In someaspects, the STA may enter the sleep or power-save mode until thebeginning of the next DI 502.

As examples, the duration ΔC of the overall interval may equalapproximately one to five seconds in some aspects. In other aspects, theoverall interval may be less than one second or more than five seconds.The duration ΔA of the DI 502 may equal approximately 16 ms in someaspects while more or less than 16 ms in other aspects. The duration ΔBof the PI may equal approximately the duration ΔA in some aspects. Inother aspects, the duration ΔB may be more or less than the duration ΔA.

FIG. 6 illustrates an exemplary communication timeline 600 in a wirelesscommunication system. The exemplary communication timeline 600 mayinclude a DI 602 of a time duration ΔA, a PI 604 of a time duration ΔB,and an overall interval of a time duration ΔC. Time increaseshorizontally across the page over the time axis.

As shown in FIG. 6, the DI 602 may include DI slots, such as DI slot616, and the PI 604 may include PI slots, such as PI slot 618. The DIslots or PI slots may facilitate a scheduled approach to access of achannel or medium during the DI 602 or the PI 604, respectively. The DIslots may each have a same duration that is known by devices in awireless communications network, and PI slots may further each have asame duration that is known by devices in a wireless communicationsnetwork. The DI slots and the PI slots may have different durations insome aspects and the same durations in other aspects. The DI slots mayrepresent periods of time when particular STAs or APs may transmit adiscovery packet or when a STA may transmit a registration requestpacket to an AP. For example, a STA may be assigned to transmit adiscovery packet during DI slot 616. The PI slots may represent periodsof time when particular STAs or APs may transmit paging request packets.For example, another STA may be assigned to transmit a paging requestpacket during PI slot 618. The DI and PI slots may have a duration equalto the time to transmit a discovery packet or paging request packet,respectively, plus a point coordination function interface space (PIFS)time.

The DI slots and PI slots may be assigned to STAs or APs using a hashcalculation of device MAC IDs in some aspects. Random time-varyingparameters may be added to the hash function so that two MAC ID's maynot repeatedly collide over time. Collaborative mechanisms, such assensing the medium and taking an empty slot, may be further utilized todetermine or assign slots. In some aspects, if a device may sense themedium as busy for a PIFS time of approximately 25 μs before the startof one slot, the device may abandon or delay transmission of a discoverypacket or a paging request packet during the slot.

Each STA or AP communicating or planning to communicate on the channelmay transmit a discovery packet at least once every particular period tonotify other devices of the STA or AP's presence on the channel.Additionally, as discussed in with respect to FIG. 5, STAs or APs mayenter a sleep or power-save mode during certain times, such as duringparticular intervals discussed in FIG. 5.

FIG. 7 illustrates an exemplary communication timeline 700 in a wirelesscommunication system. The exemplary communication timeline 700 mayinclude a DI 702 of a time duration ΔA, a PI 704 of a time duration ΔB,and an overall interval of a time duration ΔC. Time increaseshorizontally across the page over the time axis. The DI 702 and PI 704may be slotted as depicted in FIG. 7.

The beginning of the DI 702 may begin with the transmission of adiscovery start frame (DSF) packet 720 by a STA or AP. The DSF packet720 may be transmitted by contention. In some aspects, the DSF packet720 may be a discovery packet with a frame control value indicating thatthe packet is a DSF packet. The DSF packet 720 may prevent other trafficfrom communicating on the channel until a subsequent discovery packet(DP) is transmitted on the channel or during the DI 702. In otheraspects, the DSF packet 720 may be a clear to send (CTS) frame. The CTSframe may carry a Social WiFi BSSID in the address field. The durationof the DI 702 may be previously communicated to devices in some aspectswhile devices may sense the end of the DI 702 based on the absence ofcommunication on the channel for a period of time in other aspects.

The beginning of the PI 704 may begin with the transmission of a pagingstart frame (PSF) packet 722 by a STA or AP. The PSF packet 722 may betransmitted by contention. In some aspects, the PSF packet 722 may be apaging request packet with a frame control value indicating that thepacket is a PSF packet. The PSF packet 722 may prevent other trafficfrom communicating on the channel until a subsequent paging requestpacket (PR) is transmitted on the channel or during the PI 704. In otheraspects, the PSF packet 722 may be a clear to send (CTS) frame. The CTSframe may carry a Social WiFi BSSID in the address field. The start orduration of the PI 704 may be previously communicated to devices in someaspects while devices may sense the start or end of the PI 704 based onthe presence or absence of communication on the channel for a period oftime in other aspects.

In addition, as discussed with respect to FIG. 5, STAs or APs may entera sleep or power-save mode during certain times, such as duringparticular intervals.

FIG. 8 illustrates an exemplary communication timeline 800 in a wirelesscommunication system. The exemplary communication timeline 800 mayinclude a DI 802 of a time duration ΔA, a PI 804 of a time duration ΔB,and an overall interval of a time duration ΔC. Time increaseshorizontally across the page over the time axis. The DI 802 may beslotted while the PI 804 may be unslotted as shown in FIG. 8. In otheraspects, the DI 802 may be unslotted while the PI 804 may be slotted.

The beginning of the DI 802 may begin with the transmission of one ormore S-CTS packets 824 by a STA or AP. In some aspects, the S-CTS packetmay be a CTS frame with a frame control value indicating that the frameis a S-CTS packet. The S-CTS packet may prevent legacy traffic fromcommunicating on the channel during the DI 802. The start or duration ofthe DI 802 may be previously communicated to devices in some aspectswhile devices may sense the start or end of the DI 802 based on thepresence or absence of communication on the channel for a period of timein other aspects. The exemplary timeline may further include a timeduration ΔD beginning at the transmission of the first S-CTS and endingat the end of the DI 802.

The beginning of the PI 804 may begin with the transmission of a PSFpacket by a STA or AP. In some aspects, the PSF packet may be a pagingrequest packet with a frame control value indicating that the packet isa PSF packet. The PSF packet may prevent other traffic fromcommunicating on the channel until a subsequent paging request packet(PR) is transmitted on the channel or during the PI 804. In otheraspects, the PSF packet may be a clear to send (CTS) frame. The CTSframe may carry a Social WiFi BSSID in the address field. The start orduration of the PI 804 may be previously communicated to devices in someaspects while devices may sense the start or end of the PI 804 based onthe presence or absence of communication on the channel for a period oftime in other aspects. In yet other aspects, the PI 804 may begin withthe transmission of one or more S-CTS packets by a device. The pagingrequest packets transmitted during the PI 804 may be sent using acontention approach as discussed with respect to FIG. 5.

Additionally, as discussed with respect to FIG. 5, STAs or APs may entera sleep or power-save mode during certain times, such as duringparticular intervals outside of a discovery interval or paging interval.

FIG. 9 illustrates an exemplary communication timeline 900 in a wirelesscommunication system. The exemplary communication timeline 900 mayinclude a DI 902 of a time duration ΔA, a PI 904 of a time duration ΔB,and an overall interval of a time duration ΔC. Time increaseshorizontally across the page over the time axis. The DI 902 and PI 904may be slotted in some aspects as depicted in FIG. 9. In other aspects,the DI 902 or PI 904 may be unslotted as discussed with respect to FIG.5, and STAs or APs may contend to communicate on the channel.

An AP may be used to send and receive messages on behalf of one or moreSTAs in the wireless communication system. STAs may register with the APbefore the AP may send or receive messages on behalf of a STA or beforeSTAs may receive other services provided by the AP. The registrationprocess may include the STA sending a registration request packetproviding information about services provided by the STA or servicesdesired by the STA from other devices. The AP may then transmit accesspoint discovery packets (ADPs) or access point paging request packets(APRs) on behalf of the STAs, among other services.

An AP may be used to wake STAs from a sleep or power-save mode. Sincethe AP may transmit messages on behalf of STAs, STAs associated with theAP may enter a sleep or power-save mode until the AP may wake the STAswith information that a discovery packet of interest or paging requestmessage was received. The AP may use an 802.11 TIM message or broadcastTIM interval negotiation procedure, for instance, to determine when towake STAs from the sleep or power-save mode.

An AP may be used to forward information to STAs so that STAs maycommunicate directly with other STAs or APs. Since the AP maycommunicate discovery packets or paging request packets on behalf ofSTAs, the AP may directly receive responses the packets on behalf ofSTAs. The AP may then forward discovery packet or paging request packetinformation to the STA whom the AP acted on behalf of. The forwardedinformation may be transmitted in the form of a paging forward actionframe or a paging response forward action frame, or the like. In someaspects, if the STA may be unable to contact the other STAs or APs afterattempting to contact for a time-out period, the STA may terminateattempts to communicate with the other STAs and APs.

As illustrated in FIG. 9, an AP may transmit an ADP 928 during a DI 902or APR 930 during a PI 904 on behalf of a STA. When the AP may receive adiscovery packet of interest to a STA or paging request packet for aSTA, the AP may wake the STA from the sleep or power-save mode bysending an AP TIM message 932 outside of the DI or PI. In some aspects,packets transmitted outside of the DI or PI may be transmitted using acontention approach. The AP may then transmit a paging forward actionframe (PF) 934 or a paging response forward action frame (PRF) 936 tothe STA notifying the STA of the received discovery packet of interestor paging request packet for the STA. The STA may subsequentlycommunicate directly with the sender of the discovery packet or thepaging request packet. In some aspects, the AP may additionally oralternatively send the PF 934 or the PRF 936 to the sender of thediscovery packet of interest or the paging request packet, enabling thesender to directly communicate with the STA.

FIG. 10 illustrates an exemplary discovery packet 1000. As shown, theexemplary packet 1000 may include seven fields: an 11 a/n/ac/ah PHYpreamble field 1050, a frame control field 1052, a control (I) field1054, a duration field 1056, a control (II) field 1058, an expressionfield 1060, and a cyclical redundancy check field 1062. FIG. 10 furtherindicates an example size in octets of each of the fields 1050-1062.

The frame control field 1052 may include at least information about atype and subtype of the packet. The frame control field 1052 may assista parser in correctly processing and distinguishing a discovery packetfrom one or more legacy packets. The legacy packets may include anypacket not configured to be a discovery packet in some aspects. Thecontrol (I) field 1054 and the control (II) field 1058 may includecontrol information, such as an 11 bits slot number, 1 bit indicatorthat more data follows so that a STA may send additional messages aftera DI, or 1 bit indicator that more data is available so that a STA withmore data to advertise may awake or remain awake after the DI to receivepoll requests. In some aspects, the duration field 1056 may be removed.

In an example, the DI may have a maximum duration of 16 ms. Thetransmission time of the discovery packet may be 48 μs (6 Mbps at 20MHz, 11a/g preamble), plus a 25 μs PIFS. Accordingly, the total numberof discovery slots in eight DIs over 8 seconds may be approximately 1750discovery slots.

FIG. 11 illustrates an exemplary discovery packet 1100. The exemplarydiscovery packet 1100 may include the same fields as the discoverypacket 1000 except for the addition of a time stamp field 1164. Asshown, the exemplary packet 1100 may include eight fields: an11a/n/ac/ah PHY preamble field, a frame control field, a control (I)field, a duration field, a time stamp field 1164, a control (II) field,an expression field, and a cyclical redundancy check field. FIG. 11further indicates an example size in octets of each of the fields. Thetime stamp field 1164 may enable STAs to synchronize and adjust theirclocks to the highest time stamp received, for instance.

In an example, the DI may have a maximum duration of 16 ms. Thetransmission time of the discovery packet may be 52 μs (6 Mbps at 20MHz, 11a/g preamble), plus 77 μs PIFS. Accordingly, the total number ofdiscovery slots in eight DIs over 8 seconds may be approximately 1650.In other aspects, the discovery packet may include have one or moredifferent fields or values.

FIG. 12 illustrates an exemplary paging request packet 1200, which mayinclude the same fields as the discovery packet 1000 except for theaddition of a source MAC address field 1266 and the signature field 1268in place of the expression field 1060. As shown, the exemplary packet1200 may include eight fields: an 11a/n/ac/ah PHY preamble field, aframe control field, a control (I) field, a duration field, a control(II) field, a source MAC address field 1266, a signature field 1268, anda cyclical redundancy check field. FIG. 12 further indicates an examplesize in octets of each of the fields.

The paging request packet may be addressed to the sender of thediscovery packet. The signature field 1268 may include the destinationaddress and the sender MAC address. A bit in control (I) or control (II)may indicate the expected response, such as a frame including theresponder's MAC address and/or additional discovery information.

In an example, the transmission time of the paging request packet may beapproximately 77 μs (52 μs (6 Mbps at 20 MHz, 11a/g preamble) plus 25 μsPIFS). For 25 paging slots (˜number discovery slots/10), the paginginterval may be approximately 2 ms.

FIG. 13 illustrates an exemplary registration action frame 1300 that maybe used to register a STA at an AP. As shown in FIG. 13, the exemplaryregistration action frame 1300 may include five fields: a category field1370, an action field 1372, a device signature field 1374, a servicesearched field 1376, and an additional information field 1378. FIG. 13further indicates an example size in octets of each of the fields1370-1378. The additional information field 1378 may indicateinformation that may be sent outside of a PI. In some aspects, theinformation sent outside of the PI may be transmitted using a contentionapproach.

FIG. 14 illustrates an exemplary paging forwarding action frame 1400 toforward to a STA a paging request received by an AP, as discussed withrespect to FIG. 9. As shown in FIG. 14, the exemplary paging forwardingaction frame 1400 may include five fields: a category field, an actionfield, a MAC address requesting STA field 1480, a signature in pagingrequest field 1482, and an additional information field 1484. FIG. 14further indicates an example size in octets of each of the fields.

FIG. 15 illustrates an exemplary paging response forwarding action frame1500 to forward information to a STA regarding a paging responsereceived by an AP. As shown in FIG. 15, the exemplary paging forwardingaction frame 1500 may include five fields: a category field, an actionfield, a MAC address of STA from paging response field 1586, a signatureSTA sending paging response field 1588, and an additional informationfield 1590. FIG. 15 further indicates an example size in octets of eachof the fields.

FIG. 16 is a graph 1600 illustrating an example cumulative distributionfunction for successfully transmitting a discovery packet using CSMA. Inthis example, the discovery packet size was 30 octets. The contentionwindow equaled 15. The DI ranged from 9.4 ms (the leftmost functionshown on the graph 1600) to 17 ms (the rightmost function shown on thegraph 1600) for 100 STAs. These values may correspond to 1.1 times to 2times the time required to transmit 100/200 discovery packets plus PIFS.In addition, it was assumed that there are no hidden nodes in thewireless communication system (e.g., the STAs are aware of or see eachother). Based on the graph 1600, a DI duration of approximately 2 timesthe time to transmit the DPs may result in greater than 80% success whensending discovery packets.

FIG. 17 is a graph 1700 illustrating an example cumulative distributionfunction for successfully transmitting a discovery packet using CSMA. Inthis example, the discovery packet size was 30 octets. The contentionwindow equaled 15. DI ranged from 18.7 ms (the leftmost function shownon the graph 1700) to 34 ms (the rightmost function shown on the graph1700) for 200 STAs. These values may correspond to 1.1 times to 2 timesthe time required to transmit 100/200 discovery packets plus PIFS. Inaddition, it was assumed that there are no hidden nodes in the wirelesscommunication system (e.g., the STAs are aware of or see each other).Based on the graph 1700, a DI duration of approximately 2 times the timeto transmit the DPs may result in greater than 80% success when sendingdiscovery packets.

FIGS. 18 and 19 are graphs 1800, 1900 illustrating an example cumulativedistribution functions for successfully transmitting a discovery packetusing CSMA. The example values and assumptions used to prepare thesegraphs 1800, 1900 were the same as those used to prepare the graphs ofFIGS. 16 and 17. Based on these graphs 1800, 1900, it can be seen thatincreasing or decreasing the contention window may have a limited impacton successfully transmitting a discovery packet using CSMA. However,increasing the contention window value may slightly improve theprobability of successfully transmitting a discovery packet.

FIG. 20 is a graph 2000 illustrating an example probability of successfor successfully transmitting a discovery packet by random slotselection. In this example, it was assumed that there are no hiddennodes in the wireless communication system (e.g., the STAs are aware ofor see each other). Based on the graph 2000, if a random slot may beselected, a ratio of 5 times the number of STAs as slots may result in agreater than 80% chance of successfully transmitting a discovery packet.

FIG. 21 is a flowchart of an exemplary process 2100 of discoveringdevices in a wireless communication system in accordance with aspects ofthe present disclosure. The process 2100 may be used to introduce twodevices as discussed in the description of FIGS. 5, 7, and 8, forexample. Although the process 2100 is described below with respect tothe elements of the wireless device 202, other components may be used toimplement one or more of the steps described herein.

At block 2105, a discovery packet may be transmitted during a firstdiscovery interval of a plurality of discovery intervals. The discoverypacket may be configured to advertise one or more services provided in awireless communications network, such as one or more services providedby the transmitting device. The plurality of discovery intervals mayinclude recurring time intervals when multiple devices are configured totransmit and receive discovery packets. The transmission may beperformed by the transmitter 214, for example.

At block 2110, a paging packet may be received from a first deviceduring a first paging interval of a plurality of paging intervals. Thepaging packet may be configured to indicate interest in at least one ofthe services provided by the transmitting device. The plurality ofpaging intervals may include recurring time intervals when the multipledevices are configured to transmit and receive paging packets. Theplurality of paging intervals may not overlap the plurality of discoveryintervals. The receiving may be performed by receiver 212, for example.

FIG. 22 is a functional block diagram of an exemplary wireless device2200 that may be employed within the wireless communication system ofFIG. 1. The wireless device 2200 may include a transmitter 2205 fortransmitting a discovery packet during a first discovery interval. Thetransmitter 2205 may be configured to perform one or more functionsdiscussed above with respect to block 2105 of FIG. 21. The transmitter2205 may correspond to transmitter 210. The wireless device 2200 mayfurther include a receiver 2210 configured to receive a paging requestpacket from a first device during a first paging interval. The receiver2210 may be configured to perform one or more functions discussed abovewith respect to block 2110 of FIG. 21. The receiver 2210 may correspondto receiver 212.

Moreover, in one aspect, means for transmitting a discovery packetduring a first discovery interval may comprise the transmitter 2205. Inanother aspect, means for receiving a paging request from a first deviceduring a first paging interval may comprise the receiver 2210.

FIG. 23 is a flowchart of an exemplary process 2300 of discoveringdevices in a wireless communication system in accordance with aspects ofthe present disclosure. The process 2100 may be used to introduce twodevices as discussed in the description of FIGS. 5, 7, and 8, forexample. Although the process 2300 is described below with respect tothe elements of the wireless device 202, other components may be used toimplement one or more of the steps described herein.

At block 2305, a discovery packet may be received from a first deviceduring a first discovery interval of a plurality of discovery intervals.The discovery packet may be configured to advertise one or more servicesprovided by the first device. The plurality of discovery intervals mayinclude recurring time intervals when multiple devices are configured totransmit and receive discovery packets. The receiving may be performedby receiver 212, for example.

At block 2310, a paging packet may be transmitted to the first deviceduring a first paging interval of a plurality of paging intervals. Thepaging packet may be configured to indicate interest in at least one ofthe services provided by the first device. The plurality of pagingintervals may include recurring time intervals when the multiple devicesare configured to transmit and receive paging packets. The transmissionmay be performed by the transmitter 214, for example.

FIG. 24 is a functional block diagram of an exemplary wireless device2400 that may be employed within the wireless communication system ofFIG. 1. The wireless device 2400 may include a receiver 2405 forreceiving a discovery packet from a first device during a firstdiscovery interval. The receiver 2405 may be configured to perform oneor more functions discussed above with respect to block 2305 of FIG. 23.The receiver 2405 may correspond to the receiver 212. The wirelessdevice 2400 may further include a transmitter 2410 configured totransmit a paging request packet to the first device during a firstpaging interval. The transmitter 2410 may be configured to perform oneor more functions discussed above with respect to block 2310 of FIG. 23.The transmitter 2410 may correspond to transmitter 210.

Moreover, in one aspect, means for receiving a discovery packet from afirst device during a first discovery interval may comprise the receiver2405. In another aspect, means for transmitting a paging request packetto the first device during a first paging interval may comprise thetransmitter 2410.

FIG. 25 is a flowchart of an exemplary process 2500 of discoveringdevices in a wireless communication system using an access point inaccordance with aspects of the present disclosure. The process 2500 maybe used to introduce two devices as discussed in the description of FIG.9, for example. Although the process 2500 is described below withrespect to the elements of the wireless device 202, other components maybe used to implement one or more of the steps described herein.

At block 2505, a registration packet may be received from a first deviceat an access point. The registration request packet may be configured toenable the access point to transmit a discovery packet. The discoverypacket may be configured to advertise one or more services provided bythe first device in a wireless communications network. The receiving maybe performed by receiver 212, for example.

At block 2510, the first device may be registered at the access pointbased on the registration packet. The registration process may becompleted using processor unit 204, and the registration information maybe stored in memory 206, for example.

At block 2515, a discovery packet may be transmitted from the accesspoint during a first discovery interval of a plurality of discoveryintervals. The plurality of discovery intervals may include recurringtime intervals when multiple devices are configured to transmit andreceive discovery packets. The transmission may be performed by thetransmitter 214, for example.

At block 2520, a paging packet may be received from a second device atthe access point during a first paging interval of a plurality of pagingintervals. The paging request packet may be configured to indicateinterest in at least one of the services provided by the first device.The plurality of paging intervals may include recurring time intervalswhen the multiple devices are configured to transmit and receive pagingpackets. The plurality of paging intervals may not overlap with theplurality of discovery intervals. The receiving may be performed byreceiver 212, for example.

At block 2525, a notification packet may be transmitted from the accesspoint. The notification packet may be configured to enable the firstdevice and the second device to communicate directly. The transmissionmay be performed by the transmitter 214, for example.

FIG. 26 is a functional block diagram of an exemplary wireless device2600 that may be employed within the wireless communication system ofFIG. 1. The wireless device 2600 may include a processor 2605 configuredto register the first device based on the registration packet. Theprocessor 2605 may be configured to perform one or more functionsdiscussed above with respect to block 2510 of FIG. 25. The processor2605 may correspond to the processor unit 204. The wireless device 2600may further include a transmitter 2610 configured to transmit thediscovery packet during a first discovery interval and transmit anotification packet configured to enable the first device and the seconddevice to communicate directly. The transmitter 2610 may be configuredto perform one or more functions discussed above with respect to blocks2515 and 2525 of FIG. 25. The transmitter 2610 may correspond totransmitter 210. The wireless device 2600 may further include a receiver2615 configured to receive a registration request packet from a firstdevice and a paging request packet from a second device at the accesspoint during a first paging interval. The receiver 2615 may beconfigured to perform one or more functions discussed above with respectto blocks 2505 and 2520 of FIG. 25. The receiver 2615 may correspond toreceiver 212.

Moreover, in one aspect, means for receiving a registration packet froma first device and receiving a paging request from a second deviceduring a first paging interval may comprise the receiver 2615. Inanother aspect, means for registering the first device based on theregistration request packet may comprise the processor 2605. In yetanother aspect, means for transmitting the discovery packet during afirst discovery interval and transmitting a notification packetconfigured to enable the first device and the second device tocommunicate directly may comprise the transmitter 2610.

FIG. 27 is a flowchart of an exemplary process 2700 of discoveringdevices in a wireless communication system using an access point inaccordance with aspects of the present disclosure. The process 2700 maybe used to introduce two devices as discussed in the description of FIG.9, for example. Although the process 2700 is described below withrespect to the elements of the wireless device 202, other components maybe used to implement one or more of the steps described herein.

At block 2705, a registration request packet may be received from afirst device at an access point. The registration request packet may beconfigured to indicate interest in at least one of the services providedby another device in a wireless communications network. The receivingmay be performed by receiver 212, for example.

At block 2710, the first device may be registered at the access pointbased on the registration request packet. The registration process maybe completed using processor unit 204, and the registration informationmay be stored in memory 206, for example.

At block 2715, a discovery packet may be received from a second deviceat the access point during a first discovery interval. The discoverypacket may be configured to advertise one or more services provided bythe second device. The plurality of discovery intervals may includerecurring time intervals when multiple devices are configured totransmit and receive discovery packets. The receiving may be performedby receiver 212, for example.

At block 2720, a notification packet may be transmitted from the accesspoint. The notification packet may be configured to enable the firstdevice and the second device to communicate directly. The transmissionmay be performed by the transmitter 214, for example.

FIG. 28 is a functional block diagram of an exemplary wireless devicethat may be employed within the wireless communication system of FIG. 1.The wireless device 2800 may include a processor 2805 configured toregister the first device based on the registration packet. Theprocessor 2805 may be configured to perform one or more functionsdiscussed above with respect to block 2710 of FIG. 27. The processor2805 may correspond to the processor unit 204. The wireless device 2800may further include a transmitter 2810 configured to transmit anotification packet configured to enable the first device and the seconddevice to communicate directly. The transmitter 2810 may be configuredto perform one or more functions discussed above with respect to block2720 of FIG. 27. The transmitter 2810 may correspond to transmitter 210.The wireless device 2800 may further include a receiver 2815 configuredto receive a registration request packet from a first device and adiscovery packet from a second device during a first discovery intervalof a plurality of discovery intervals. The plurality of discoveryintervals may include recurring time intervals when multiple devices areconfigured to transmit and receive discovery packets. The receiver 2815may be configured to perform one or more functions discussed above withrespect to blocks 2705 and 2715 of FIG. 27. The receiver 2815 maycorrespond to receiver 212.

Moreover, in one aspect, means for receiving a registration packet froma first device and receiving a discovery packet from a second deviceduring a discovery interval may comprise the receiver 2815. In anotheraspect, means for registering the first device based on the registrationrequest packet may comprise the processor 2805. In yet another aspect,means for transmitting a notification packet configured to enable thefirst device and the second device to communicate directly may comprisethe transmitter 2810.

FIG. 29 is a flowchart of an exemplary process 2900 of discoveringdevices in a wireless communication system using an access point inaccordance with aspects of the present disclosure. The process 2900 maybe used to introduce two devices as discussed in the description of FIG.9, for example. Although the process 2900 is described below withrespect to the elements of the wireless device 202, other components maybe used to implement one or more of the steps described herein.

At block 2905, a registration request packet may be transmitted from afirst device to an access point. The registration request packet may beconfigured to register the first device at the access point and enablethe access point to transmit a discovery packet during a first discoveryinterval of a plurality of discovery intervals. The discovery packet maybe configured to advertise one or more services provided by the firstdevice. The plurality of discovery intervals may include recurring timeintervals when multiple devices are configured to transmit and receivediscovery packets. Further, the registration packet may be configured toregister the first device at the access point and indicate interest inone or more services provided by a different device. The transmissionmay be performed by the transmitter 214, for example.

At block 2910, a notification packet may be received from the accesspoint or a second device. The notification packet may be configured toindicate interest in at least one of the services provided by the firstdevice and enable the first device and the second device to communicatedirectly. Further, the notification packet may be configured to indicatethat the second device provides at least one service indicated ofinterest to the first device based on the registration packet. Thereceiving may be performed by receiver 212, for example.

FIG. 30 is a functional block diagram of an exemplary wireless device3000 that may be employed within the wireless communication system ofFIG. 1. The wireless device 3000 may include a transmitter 3005 fortransmitting a registration packet from a first device to an accesspoint. The transmitter 3005 may be configured to perform one or morefunctions discussed above with respect to block 2905 of FIG. 29. Thetransmitter 3005 may correspond to the transmitter 210. The wirelessdevice 3000 may further include a receiver 3010 configured to receivefrom the access point or a second device a notification packetconfigured to indicate interest in at least one of the services providedby the first device or that the second device provides at least oneservice indicated of interest to the first device based on theregistration packet. In addition, the notification packet may enable thefirst device and the second device to communicate directly. The receiver3010 may be configured to perform one or more functions discussed abovewith respect to block 2910 of FIG. 29. The receiver 3010 may correspondto receiver 212.

Moreover, in one aspect, means for transmitting a registration requestpacket to an access point may comprise the transmitter 3005. In anotheraspect, means for receiving from the access point or a second device anotification packet may comprise the receiver 3010.

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like. Further, a “channel width” as used herein may encompass ormay also be referred to as a bandwidth in certain aspects.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover: a, b, c,a-b, a-c, b-c, and a-b-c.

The various operations of methods described above may be performed byany suitable means capable of performing the operations, such as varioushardware and/or software component(s), circuits, and/or module(s).Generally, any operations illustrated in the Figures may be performed bycorresponding functional means capable of performing the operations.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array signal (FPGA) or other programmable logic device(PLD), discrete gate or transistor logic, discrete hardware componentsor any combination thereof designed to perform the functions describedherein. A general purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

In one or more aspects, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over as oneor more instructions or code on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media may be anyavailable media that can be accessed by a computer. By way of example,and not limitation, such computer-readable media can comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Thus, in some aspects computer readable medium may comprisenon-transitory computer readable medium (e.g., tangible media). Inaddition, in some aspects computer readable medium may comprisetransitory computer readable medium (e.g., a signal). Combinations ofthe above should also be included within the scope of computer-readablemedia.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

The functions described may be implemented in hardware, software,firmware or any combination thereof. If implemented in software, thefunctions may be stored as one or more instructions on acomputer-readable medium. A storage media may be any available mediathat can be accessed by a computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For certain aspects, the computer program product may includepackaging material.

Software or instructions may also be transmitted over a transmissionmedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition oftransmission medium.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

While the foregoing is directed to aspects of the present disclosure,other and further aspects of the disclosure may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. A method of wireless communication performed byan apparatus, the method comprising: receiving an indication of a firststart time for a first discovery interval of a plurality of discoveryintervals, a first duration for the first discovery interval, a secondstart time for a first paging interval of a plurality of pagingintervals, and a second duration for the first paging interval;transmitting a discovery packet during the first discovery interval ofthe plurality of discovery intervals, the discovery packet advertising aservice provided in a wireless communications network, the plurality ofdiscovery intervals comprising recurring time intervals when a pluralityof devices are configured to transmit and receive discovery packets, theplurality of devices being aware of the first start time and the firstduration; and receiving a paging packet from a first device during afirst paging interval of a plurality of paging intervals, the pagingpacket indicating interest in the service, the plurality of pagingintervals comprising recurring time intervals when the plurality ofdevices are configured to transmit and receive paging packets, theplurality of devices being aware of the second start time and the secondduration, the plurality of paging intervals not overlapping theplurality of discovery intervals.
 2. The method of claim 1, wherein thediscovery packet is configured to advertise a first service provided bythe apparatus, and the paging packet is configured to indicate interestin the first service provided by the apparatus.
 3. The method of claim2, further comprising: determining when to transmit the discovery packetbased on contention for a wireless communication medium; and delayingthe contention until after a delay period determined based at least inpart on a random value.
 4. The method of claim 2, wherein the apparatusis configured to enter a power-save mode at times other than theplurality of discovery intervals and the plurality of paging intervalsunless the apparatus is scheduled to communicate at times other than theplurality of discovery intervals and the plurality of paging intervals.5. The method of claim 2, wherein said transmitting the discovery packetduring the first discovery interval comprises transmitting the discoverypacket during a first sub-interval of a plurality of sub-intervals ofthe first discovery interval, each sub-interval being of a same durationthat is known by the plurality of devices.
 6. The method of claim 5,further comprising determining the first sub-interval based oncontention for a wireless communication medium.
 7. The method of claim5, further comprising determining the first sub-interval based on ascheduled sub-interval received from another device.
 8. The method ofclaim 2, wherein said receiving the paging packet from the first deviceduring the first paging interval comprises receiving the paging packetduring a scheduled sub-interval of a plurality of sub-intervals of thefirst paging interval, each sub-interval being of a same duration thatis known by the plurality of devices.
 9. The method of claim 2, whereinthe discovery packets transmitted during the plurality of discoveryintervals have a fixed size and comprise at least one of a data frame, amanagement frame, and a management action frame.
 10. The method of claim9, wherein the discovery packets transmitted during the plurality ofdiscovery intervals comprise a timestamp field configured to enable theplurality of devices to synchronize clocks.
 11. The method of claim 2,wherein the discovery packets transmitted during the plurality ofdiscovery intervals include discovery information generated by a higherlayer discovery protocol or an application-based discovery protocol. 12.The method of claim 2, wherein the paging packets transmitted during theplurality of paging intervals have a fixed size and comprise a sourceaddress field and a recipient address field.
 13. The method of claim 2,wherein a wireless communication medium is cleared of transmissionsother than discovery packets during the plurality of discoveryintervals, and the wireless communication medium is cleared oftransmissions other than paging packets during the plurality of pagingintervals.
 14. The method of claim 13, further comprising transmitting apacket comprising a clear to send frame to clear the wirelesscommunication medium of transmissions other than discovery packetsduring the first discovery interval and indicate a start of the firstdiscovery interval.
 15. The method of claim 1, further comprising:receiving a registration packet from a second device, the registrationpacket configured to enable the apparatus to transmit the discoverypacket, the discovery packet configured to advertise a first serviceprovided by the second device; and transmitting a notification packetconfigured to enable the first device and the second device tocommunicate directly, wherein the paging packet is configured toindicate interest in the first service provided by the second device.16. The method of claim 15, further comprising: transmitting apower-save message configured to instruct the first device to enter apower-save mode; and transmitting an awaken message configured toinstruct the first device to leave a power-save mode, the awaken messagecomprising a traffic indication message.
 17. The method of claim 15,wherein said transmitting the notification packet comprises transmittingthe notification packet to the first device.
 18. The method of claim 17,wherein the notification packet comprises a page forward frameconfigured to forward the paging packet received from the second device.19. The method of claim 15, wherein said transmitting the notificationpacket comprises transmitting the notification packet to the seconddevice.
 20. A method of discovering devices in a wireless communicationsystem performed by an apparatus, the method comprising: receiving anindication of a first start time for a first discovery interval of aplurality of discovery intervals, a first duration for the firstdiscovery interval, a second start time for a first paging interval of aplurality of paging intervals, and a second duration for the firstpaging interval; receiving a discovery packet from a first device duringthe first discovery interval of the plurality of discovery intervals,the discovery packet advertising a service provided by the first devicein a wireless communications network, the plurality of discoveryintervals comprising recurring time intervals when a plurality ofdevices are configured to transmit and receive discovery packets, theplurality of devices being aware of the first start time and the firstduration; and transmitting a paging packet to the first device during afirst paging interval of a plurality of paging intervals, the pagingpacket indicating interest in the service provided by the first device,the plurality of paging intervals comprising recurring time intervalswhen the plurality of devices are configured to transmit and receivepaging packets, the plurality of devices being aware of the second starttime and the second duration, the plurality of paging intervals notoverlapping the plurality of discovery intervals.
 21. The method ofclaim 20, further comprising: determining when to transmit the pagingpacket based on contention for a wireless communication medium; anddelaying the contention until after a delay time determined based atleast in part on a random value.
 22. The method of claim 20, wherein theapparatus is configured to enter a power-save mode at times other thanthe plurality of discovery intervals and the plurality of pagingintervals unless the apparatus is scheduled to communicate at timesother than the plurality of discovery intervals and the plurality ofpaging intervals.
 23. The method of claim 20, wherein said receiving thediscovery packet during the first discovery interval comprises receivingthe discovery packet during a first scheduled sub-interval of aplurality of sub-intervals of the first discovery interval, eachsub-interval being of a same time duration that is known by theplurality of devices.
 24. The method of claim 20, wherein saidtransmitting the paging packet to the first device during the firstpaging interval comprises transmitting the paging packet during a firstsub-interval of a plurality of sub-intervals of the first paginginterval, each sub-interval being of a same time duration that is knownby the plurality of devices.
 25. The method of claim 24, furthercomprising determining the first sub-interval based on contention for awireless communication medium.
 26. The method of claim 24, furthercomprising determining the first sub-interval based on a scheduledsub-interval received from another device.
 27. The method of claim 20,wherein the discovery packets transmitted during the plurality ofdiscovery intervals have a fixed size and comprise at least one of adata frame, a management frame, and a management action frame.
 28. Themethod of claim 20, wherein the discovery packet from the first deviceindicates a start of the first paging interval.
 29. The method of claim20, wherein the discovery packet includes discovery informationgenerated by a higher layer discovery protocol or an application-baseddiscovery protocol.
 30. The method of claim 20, wherein the pagingpackets transmitted during the plurality of paging intervals have afixed size and comprise a source address field and a recipient addressfield.
 31. The method of claim 20, wherein a wireless communicationmedium is cleared of transmissions other than discovery packets duringthe plurality of discovery intervals, and the wireless communicationmedium is cleared of transmissions other than paging packets during theplurality of paging intervals.
 32. An apparatus operable in a wirelesscommunication system comprising: a transmitter configured to transmit adiscovery packet during a first discovery interval of a plurality ofdiscovery intervals, the discovery packet advertising a service providedin a wireless communications network, the plurality of discoveryintervals comprising recurring time intervals when a plurality ofdevices are configured to transmit and receive discovery packets, theplurality of devices being aware of a first start time for the firstdiscovery interval and a first duration for the first discoveryinterval; and a receiver configured to receive an indication of thefirst start time, the first duration, a second start time for the firstpaging interval, and a second duration for the first paging interval,and receive a paging packet from a first device during a first paginginterval of a plurality of paging intervals, the paging packetindicating interest in the service, the plurality of paging intervalscomprising recurring time intervals when the plurality of devices areconfigured to transmit and receive paging packets, the plurality ofdevices being aware of a second start time for the first paging intervaland a second duration for the first paging interval, the plurality ofpaging intervals not overlapping the plurality of discovery intervals.33. The apparatus of claim 32, wherein the discovery packet isconfigured to advertise a first service provided by the apparatus, andthe paging packet is configured to indicate interest in the firstservice provided by the apparatus.
 34. The apparatus of claim 33,further comprising a processor configured to: determine when to transmitthe discovery packet based on contention for a wireless communicationmedium; and delay the contention until after a delay period determinedbased at least in part on a random value.
 35. The apparatus of claim 33,wherein the apparatus is configured to enter a power-save mode at timesother than the plurality of discovery intervals and the plurality ofpaging intervals unless the apparatus is scheduled to communicate attimes other than the plurality of discovery intervals and the pluralityof paging intervals.
 36. The apparatus of claim 33, wherein thetransmitter is configured to transmit the discovery packet during afirst sub-interval of a plurality of sub-intervals of the firstdiscovery interval, each sub-interval being of a same duration that isknown by the plurality of devices.
 37. The apparatus of claim 36,further comprising a processor configured to determine the firstsub-interval based on contention for a wireless communication medium.38. The apparatus of claim 36, further comprising a processor configuredto determine the first sub-interval based on a scheduled sub-intervalreceived from another device.
 39. The apparatus of claim 33, wherein thereceiver is configured to receive the paging packet during a scheduledsub-interval of a plurality of sub-intervals of the first paginginterval, each sub-interval being of a same duration that is known bythe plurality of devices.
 40. The apparatus of claim 33, wherein thediscovery packets transmitted during the plurality of discoveryintervals have a fixed size and comprise at least one of a data frame, amanagement frame, and a management action frame.
 41. The apparatus ofclaim 40, wherein the discovery packets transmitted during the pluralityof discovery intervals comprise a timestamp field configured to enablethe plurality of devices to synchronize clocks.
 42. The apparatus ofclaim 40, wherein the discovery packets transmitted during the pluralityof discovery intervals include discovery information generated by ahigher layer discovery protocol or an application-based discoveryprotocol.
 43. The apparatus of claim 33, wherein the paging packetstransmitted during the plurality of paging intervals have a fixed sizeand comprise a source address field and a recipient address field. 44.The apparatus of claim 33, wherein a wireless communication medium iscleared of transmissions other than discovery packets during theplurality of discovery intervals, and the wireless communication mediumis cleared of transmissions other than paging packets during theplurality of paging intervals.
 45. The apparatus of claim 44, whereinthe transmitter is further configured to transmit a packet comprising aclear to send frame to clear the wireless communication medium oftransmissions other than discovery packets during the first discoveryinterval and indicate a start of the first discovery interval.
 46. Theapparatus of claim 32, wherein the receiver is further configured toreceive a registration packet from a second device, the registrationpacket configured to enable the apparatus to transmit the discoverypacket, the discovery packet configured to advertise a first serviceprovided by the second device; and the transmitter is further configuredto transmit a notification packet configured to enable the first deviceand the second device to communicate directly, wherein the paging packetis configured to indicate interest in the first service provided by thesecond device.
 47. The apparatus of claim 46, further comprising:transmitting a power-save message configured to instruct the firstdevice to enter a power-save mode; and transmitting an awaken messageconfigured to instruct the first device to leave a power-save mode, theawaken message comprising a traffic indication message.
 48. The methodof claim 46, wherein said transmitting the notification packet comprisestransmitting the notification packet to the first device.
 49. The methodof claim 48, wherein the notification packet comprises a page forwardframe configured to forward the paging packet received from the seconddevice.
 50. The method of claim 46, wherein said transmitting thenotification packet comprises transmitting the notification packet tothe second device.
 51. An apparatus operable in a wireless communicationsystem comprising: a receiver configured to receive an indication of afirst start time for a first discovery interval of a plurality ofdiscovery intervals, a first duration for the first discovery interval,a second start time for a first paging interval of a plurality of pagingintervals, and a second duration for the first paging interval, andreceive a discovery packet from a first device during the firstdiscovery interval of the plurality of discovery intervals, thediscovery packet advertising a service provided by the first device in awireless communications network, the plurality of discovery intervalscomprising recurring time intervals when a plurality of devices areconfigured to transmit and receive discovery packets, the plurality ofdevices being aware of the first start time and the first duration; anda transmitter configured to transmit a paging packet to the first deviceduring a first paging interval of a plurality of paging intervals, thepaging packet indicating interest in the service provided by the firstdevice, the plurality of paging intervals comprising recurring timeintervals when the plurality of devices are configured to transmit andreceive paging packets, the plurality of devices being aware of thesecond start time and the second duration, the plurality of pagingintervals not overlapping the plurality of discovery intervals.
 52. Theapparatus of claim 51, further comprising processor configured to:determine when to transmit the paging packet based on contention for awireless communication medium; and delay the contention until after adelay time determined based at least in part on a random value.
 53. Theapparatus of claim 51, wherein the apparatus is configured to enter apower-save mode at times other than the plurality of discovery intervalsand the plurality of paging intervals unless the apparatus is scheduledto communicate at times other than the plurality of discovery intervalsand the plurality of paging intervals.
 54. The apparatus of claim 51,wherein the receiver is configured to receive the discovery packetduring a first scheduled sub-interval of a plurality of sub-intervals ofthe first discovery interval, each sub-interval being of a same timeduration that is known by the plurality of devices.
 55. The apparatus ofclaim 51, wherein the transmitter is configured to transmit the pagingpacket during a first sub-interval of a plurality of sub-intervals ofthe first paging interval, each sub-interval being of a same timeduration that is known by the plurality of devices.
 56. The apparatus ofclaim 55, further comprising a processor configured to determine thefirst sub-interval based on contention for a wireless communicationmedium.
 57. The apparatus of claim 55, further comprising a processorconfigured to determine the first sub-interval based on a scheduledsub-interval received from another device.
 58. The apparatus of claim51, wherein the discovery packets transmitted during the plurality ofdiscovery intervals have a fixed size and comprise at least one of adata frame, a management frame, and a management action frame.
 59. Theapparatus of claim 51, wherein the discovery packet from the firstdevice indicates a start of the first paging interval.
 60. The apparatusof claim 51, wherein the discovery packet includes discovery informationgenerated by a higher layer discovery protocol or an application-baseddiscovery protocol.
 61. The apparatus of claim 51, wherein the pagingpackets transmitted during the plurality of paging intervals have afixed size and comprise a source address field and a recipient addressfield.
 62. The apparatus of claim 51, wherein a wireless communicationmedium is cleared of transmissions other than discovery packets duringthe plurality of discovery intervals, and the wireless communicationmedium is cleared of transmissions other than paging packets during theplurality of paging intervals.
 63. An apparatus operable in a wirelesscommunication system comprising: means for receiving an indication of afirst start time for a first discovery interval of a plurality ofdiscovery intervals, a first duration for the first discovery interval,a second start time for a first paging interval of a plurality of pagingintervals, and a second duration for the first paging interval; meansfor transmitting a discovery packet during the first discovery intervalof the plurality of discovery intervals, the discovery packetadvertising a service provided in a wireless communications network, theplurality of discovery intervals comprising recurring time intervalswhen a plurality of devices are configured to transmit and receivediscovery packets, the plurality of devices being aware of the firststart time and the first duration; and means for receiving a pagingpacket from a first device during a first paging interval of a pluralityof paging intervals, the paging packet indicating interest in theservice, the plurality of paging intervals comprising recurring timeintervals when the plurality of devices are configured to transmit andreceive paging packets, the plurality of devices being aware of thesecond start time and the second duration, the plurality of pagingintervals not overlapping the plurality of discovery intervals.
 64. Anapparatus operable in a wireless communication system comprising: meansfor receiving an indication of a start time and a duration for a firstdiscovery interval of a plurality of discovery intervals, the start timeand the duration shared among a plurality of devices; means forreceiving a discovery packet from a first device during the firstdiscovery interval of the plurality of discovery intervals, thediscovery packet advertising a service provided by the first device in awireless communications network, the plurality of discovery intervalscomprising recurring time intervals when a plurality of devices areconfigured to transmit and receive discovery packets, the plurality ofdevices being aware of the first start time and the first duration; andmeans for transmitting a paging packet to the first device during afirst paging interval of a plurality of paging intervals, the pagingpacket indicating interest in the service provided by the first device,the plurality of paging intervals comprising recurring time intervalswhen the plurality of devices are configured to transmit and receivepaging packets, the plurality of devices being aware of the second starttime and the second duration, the plurality of paging intervals notoverlapping the plurality of discovery intervals.
 65. A non-transitorycomputer-readable medium comprising instructions that when executedcause an apparatus to: receive an indication of a start time and aduration for a first discovery interval of a plurality of discoveryintervals, the start time and the duration shared among a plurality ofdevices; transmit a discovery packet during the first discovery intervalof the plurality of discovery intervals, the discovery packetadvertising a service provided in a wireless communications network, theplurality of discovery intervals comprising recurring time intervalswhen a plurality of devices are configured to transmit and receivediscovery packets, the plurality of devices being aware of the firststart time and the first duration; and receive a paging packet from afirst device during a first paging interval of a plurality of pagingintervals, the paging packet indicating interest in the service, theplurality of paging intervals comprising recurring time intervals whenthe plurality of devices are configured to transmit and receive pagingpackets, the plurality of devices being aware of the second start timeand the second duration, the plurality of paging intervals notoverlapping the plurality of discovery intervals.
 66. A non-transitorycomputer-readable medium comprising instructions that when executedcause an apparatus to: receive an indication of a start time and aduration for a first discovery interval of a plurality of discoveryintervals, the start time and the duration shared among a plurality ofdevices; receive a discovery packet from a first device during the firstdiscovery interval of the plurality of discovery intervals, thediscovery packet advertising a service provided by the first device in awireless communications network, the plurality of discovery intervalscomprising recurring time intervals when a plurality of devices areconfigured to transmit and receive discovery packets, the plurality ofdevices being aware of the first start time and the first duration; andtransmit a paging packet to the first device during a first paginginterval of a plurality of paging intervals, the paging packetindicating interest in the service provided by the first device, theplurality of paging intervals comprising recurring time intervals whenthe plurality of devices are configured to transmit and receive pagingpackets, the plurality of devices being aware of the second start timeand the second duration, the plurality of paging intervals notoverlapping the plurality of discovery intervals.